Hiring the wrong people! If you get this wrong it can waste not only cash but resources and opportunity cost.
So we suggest:-
That you prepare a job description in writing, together with a list of detailed skills required to carry out the job.
Never accept any test of skills carried out by an agency, always re-test yourself.
Ensure that several people within your organisation interview prospective employees.
Obtain oral references, if possible.
Read and re-read CV.
Always have a minimum of six months probationary period.
Hire slowly, fire quickly!